Viva Origino
Online ISSN : 1346-6933
Print ISSN : 0910-4003
Volume 35, Issue 2
Displaying 1-3 of 3 articles from this issue
  • Hideo Hashizume
    2007 Volume 35 Issue 2 Pages 60-65
    Published: 2007
    Released on J-STAGE: January 18, 2022
    JOURNAL FREE ACCESS

      Adsorption of 10 types of amino acids (Gly, Ala, Val, Leu, Ile, Pro, Ser, Asp, Glu, and Phe) has been studied using chrysotile, which is a mineral belonging to the serpentine group. The adsorption of Asp and Glu by chrysotile was strong while Gly, Ala, Val, Leu, Ile, Pro, Ser and Phe were hardly adsorbed by chrysotile. It was found that adsorption behavior of these amino acids was mainly affected by the dissociation behavior of the adsorbent and the adsorbates, and also by the solubility of the adsorbate into water. Around at pH 8, chrysotile would have positive charges, and Asp and Glu possessed negative charges. Therefore, Asp and Glu could be adsorbed well on chrysotile by electrostatic interaction. It was shown that the adsorption of amino acids was inversely correlated with their solubility into water. The adsorption behavior of amino acids by chrysotile could be explained on the basis of the dissociation of amino acids and their solubility into water. This trend of the adsorption behavior of amino acids by chrysotile was similar to that by kaolinite [9]. This fact suggested that chrysotile would possess the similarity of crystal structure to kaolinite. Additionally, chiral separation of D- and L-amino acid would be difficult by chrysotile.

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  • Arvydas Tamulis, Vykintas Tamulis
    2007 Volume 35 Issue 2 Pages 66-72
    Published: 2007
    Released on J-STAGE: January 18, 2022
    JOURNAL FREE ACCESS

      We used quantum mechanical (QM) electron correlation interactions density functional theory (DFT) methods (i.e. high precision quantum mechanical calculations) to investigate self-assembled photoactive bioorganic system of artificial minimal living cell. The cell system studied is based on peptide nucleic acid (PNA) and consists of 333 atoms (not including the associated water solvent shells) and is 3.0 nm in diameter. The electron correlations interaction originating the hydrogen bonds and Van der Waals weak chemical bonds that increase due to the addition of a polar solvent (water) molecules, fatty acid (FA), precursor fatty acid (pFA) molecules and waste pieces of the pFA molecules play a critical role in the QM interaction based self-assembly of the photosynthetic center and functioning of the photosynthetic processes of the artificial minimal living cell. The distances between the separated sensitizer, precursor fatty acid, and water molecules are comparable to Van der Waals and hydrogen bonding radii. As a result these nonlinear quantum interactions compress the overall system resulting in a smaller gap between the HOMO and LUMO electron energy levels and photoexcited electron tunneling occurs from the sensitizer a 1,4-bis (N, N-dimethylamino) naphthalene to pFA molecules. The electron tunneling and associated light absorption of most intense transition as calculated by the time dependent density functional theory (TD DFT) method differs from spectroscopic experiments by only 0.3 nm, which is within the value of experiment errors. This agreement implies that the quantum mechanically self-assembled structure of minimal cell very closely approximates the realistic one.

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  • Mikio Shimizu
    2007 Volume 35 Issue 2 Pages 73-81
    Published: 2007
    Released on J-STAGE: January 18, 2022
    JOURNAL FREE ACCESS

      It was found that cysteine or its ester can enhance various reaction rates in the TCA cycle such as aconitase, isocitrate dehydrogenase, succinate dehydrogenase, and fumarase and that histidine or its ester can enhance those such as succinate CoA synthetase and citrate synthase. Histidine or its ester can also enhance the reaction rates for carbonyl aspartate dehydrogenase, 2-keto-3-deoxy octonate aldolase, and acetoacetate decarboxylase. These findings for the origins of metabolism as well as those for the origins of the genetic code and the central metabolic pathway in our recent publications [2-4] suggest that life would have started from a system of amino acids and anticodonic tri-ribonucleotides. Some possible routes to the contemporary biosystem from this “genetic code world” were discussed.

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